A number of factors have led to the development of high performance elevators. Taller buildings and increased passenger traffic requires efficient elevator systems to convey passengers between floors. This requires advanced, faster elevators with a sophisticated system for powering and controlling the elevator. This has resulted in elevators having ever increasing vertical operating speeds. However, such faster travel speeds have led to a number of technical challenges. One such technical challenge is the need for precisely aligned guide rails. These guide rails, upon which the elevator cars move vertically, must be aligned to exacting tolerances. If the opposing rails are not aligned this could be detected by passengers riding in the elevator car as vibration. This may result in passenger discomfort and wear and tear on elevator parts.
To alleviate these problems in elevator operation, the rails must be positioned as linear and parallel to one another as is practical. A number of different devices have been employed to ensure proper orientation of the elevator rails on the vertical services within elevator shafts. In one common technique, a plumb line may be hung adjacent to the brackets onto which the guide rails are mounted. This plumb line may then be used to ensure proper orientation of the rail from top to bottom. This is referred to as “plumb alignment”.
A second device may be used to ensure orientation of the point of the rails. This ensures that each elevator guide rail is positioned such that it properly faces the opposite guide rail. This is referred to as “point alignment”.
U.S. Pat. No. 4,593,794 provides an illustration of one such rail orientation device. The term used herein to describe the pointing of rails such that they face each other is “point leveling”.
U.S. Pat. No. 4,593,794 discloses an apparatus for installing elevator rails in a linear and parallel orientation. The device disclosed includes a pair of mirror image guide clamps which each attach to one opposite rail. These guide assemblies have a reference notch which positions the rail relative to an adjacent plumb line. The device also includes an inner connecting guideline which ensures that the point orientation of the rails of the rail clamp location is aligned. This requires attaching a guide to each rail and having a string extend between the two guides. Thus for proper rail point alignment at least two guides must be clamped to opposite rails, a string extends across the elevator shaft, and additional tools are required for plumb alignment. The combination of multiple clamps and multiple strings allows both plumb and point alignment using this tool.
A number of drawbacks exist for the use of string-based alignment. First, the alignment of point requires a rail installer to move back and forth between the two rails making multiple adjustment to each string guide. Secondly, the string is somewhat cumbersome. The string extends across the elevator shaft and the installers must move around a string extending across the elevator shaft.
One of the present objects is to design a elevator rail point alignment tool that requires only one device be attached to a rail for point alignment.